lib: introduce initial implementation of object aggregation manager

This lib tracks objects which could be of two types:
1) root object
2) nested object - with a "delta" which differentiates it from
                   the associated root object
The objects are tracked by a hashtable and reference-counted. User is
responsible of implementing callbacks to create/destroy root entity
related to each root object and callback to create/destroy nested object
delta.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 46 insertions, 0 deletions

diff --git a/include/linux/objagg.h b/include/linux/objagg.h
new file mode 100644
index 000000000000..34f38c186ea0
--- /dev/null
+++ b/include/linux/objagg.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 */
+/* Copyright (c) 2018 Mellanox Technologies. All rights reserved */
+
+#ifndef _OBJAGG_H
+#define _OBJAGG_H
+
+struct objagg_ops {
+	size_t obj_size;
+	void * (*delta_create)(void *priv, void *parent_obj, void *obj);
+	void (*delta_destroy)(void *priv, void *delta_priv);
+	void * (*root_create)(void *priv, void *obj);
+	void (*root_destroy)(void *priv, void *root_priv);
+};
+
+struct objagg;
+struct objagg_obj;
+
+const void *objagg_obj_root_priv(const struct objagg_obj *objagg_obj);
+const void *objagg_obj_delta_priv(const struct objagg_obj *objagg_obj);
+const void *objagg_obj_raw(const struct objagg_obj *objagg_obj);
+
+struct objagg_obj *objagg_obj_get(struct objagg *objagg, void *obj);
+void objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj);
+struct objagg *objagg_create(const struct objagg_ops *ops, void *priv);
+void objagg_destroy(struct objagg *objagg);
+
+struct objagg_obj_stats {
+	unsigned int user_count;
+	unsigned int delta_user_count; /* includes delta object users */
+};
+
+struct objagg_obj_stats_info {
+	struct objagg_obj_stats stats;
+	struct objagg_obj *objagg_obj; /* associated object */
+	bool is_root;
+};
+
+struct objagg_stats {
+	unsigned int stats_info_count;
+	struct objagg_obj_stats_info stats_info[];
+};
+
+const struct objagg_stats *objagg_stats_get(struct objagg *objagg);
+void objagg_stats_put(const struct objagg_stats *objagg_stats);
+
+#endif